This application claims the priority of German Patent Document 199 59 594.1, filed Dec. 10, 1999, the disclosure of which is expressly incorporated by reference herein.
This invention relates to a chain drive of a V-engine having overhead camshafts which are driven by a crankshaft, in each case, by a separate chain, in which case tensioner blades swivellably assigned to a respective slack run of the chains are acted upon by hydraulic chain tensioners of the same type of construction.
A chain drive of this type for a V-engine is known, for example, from German Patent Document DE 39 21 775 A1. The tensioner blades acting upon the respective slack run of the respective chain are in each case acted upon by chain tensioners which are arranged between the slack run and the tension run of the respective chain on the respective face of a pertaining face of a pertaining cylinder bank and of the pertaining cylinder head. These chain tensioners, which, because of their arrangement, have the same construction, are therefore not easily accessible if required.
It is an object of the invention to provide, for a chain drive of the above-mentioned type having chain tensioners accessible from the outside, an arrangement therefor as well as a further development for chain tensioners of the same construction on V-engines.
This object is achieved by the tensioner blades having in their free end areas contact ramps for spherically designed end sections on tensioning pistons of the chain tensioners of the same construction, which contact ramps are arranged in a sloped manner such that the first chain tensioner is arranged in the area of an inlet-side longitudinal side of a first cylinder head and the second chain tensioner is arranged in the area of an outlet-side longitudinal side of a second cylinder head, wherein the chain tensioners which are arranged with respect to one another essentially in a transverse direction with a vertically aligned to vertically sloped first chain tensioner and a horizontally aligned to horizontally sloped second chain tensioner in each case are equipped with leakage devices used for different venting directions, in both end areas of each tensioning piston.
By the design according to the invention of the tensioner blades with contact ramps arranged in a sloped manner and known per se from German Patent Document DE 42 06 071 C2, for spherically designed end sections of the tensioning pistons, the chain tensioners can be arranged in an advantageous manner to be accessible from the outside or mountable relative to the housing of the respective V-engine. According to an advantageous feature of preferred embodiments of the invention, the chain tensioners are arranged with respect to one another in a transverse direction and each of the chain tensioners of the same construction has two mutually independently operating leakage devices, for the advantageous venting of the chain tensioners in the respective installed position.
Advantageous features of preferred embodiments of the invention are described in the claims.
The invention will be described by an embodiment illustrated in the drawing.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.